If you read science fiction (and some of us here read A LOT of science fiction), you must be familiar with the concept of a wormhole. A wormhole is a rip in spacetime that allows one to travel to far away places instantly. Say, you want to got to Cleveland (we realize that nobody wants to go to Cleveland, but this is highly hypothetical). You step into a wormhole, and hello the polluted shores of Lake Erie!
Did we just say "hypothetical"? Let's take that back. Wormholes are real. No, there is not one in your backyard, but they are theoretically possible. In fact, take a look in your backyard to be sure. No wormhole? Oh well.
But even though no wormhole has been observed (yet), they can exist. The concept was created by none other than Albert Einstein (so clearly, there is credibility there) and Nathan Rosen. In fact, the wormhole's original name was Einstein-Rosen bridge.
So be careful! Who knows, you might run into the first non-theoretical wormhole and end up in Timbuktu, Titan, or Tralfamadore. Or Cleveland. You definitely don't want to end up in Cleveland...